09/05/2016 09:27 BST | Updated 07/05/2017 06:12 BST

Five Things We Learned About Fitness in April

April has seen another deluge of brand new and excellent research into health and fitness. In a continuation of our series, here are five things we learned in April, which you can take away and start using immediately!

1. Inter-set rest periods are important when using heavy loads (3-5RM) Resting between sets when working within this rep range allows you to achieve a higher number of reps across the workout with a constant load. Rest for two minutes for single joint exercises, like bicep curls or leg extenstions, but for three to five minutes for multi-joint exercises, including the bench press and the squat.

2. You should create an energy deficit through exercise, not diet!

Creating an energy deficit from diet rather than exercise led to a greater desire to eat, making weight loss much more difficult. Researchers found that using diet alone to create a 25 per cent reduction in energy balance over three days led to an increased desire to eat, elevated hunger levels, as well as a heightened sense of food reward. Those who created a deficit with aerobic training were much less likely to have these symptoms, and didn't experience them so severely.

3. There may be no such thing as a hypertrophy range

It's commonly said in fitness that if your goal is to build muscle, then you should train at a range between 65 and 95 per cent of your 1RM for 8-12 reps. But a recent study in the Journal of Strength and Conditioning has questioned this, and refuted the idea that a hypertrophy range actually exists. The study showed similar hypertrophy in subjects training using a 10 per cent RM load vs. a 30 per cent RM load across an eight week training block. This is one of the first studies to show that using low loads may be equally as beneficial for muscle size training as using much heavier loads. If your goal is to maximize overall muscle size, then training over a wide spectrum of rep ranges would be beneficial. High intensity training stimulates fast twitch fiber growth, while lower intensity training will enhance the slow twitch fibres.

4. You may only need to train each muscle group twice per week

A new paper on training frequency and its impact on hypertrophy (muscle growth) showed that when volume per muscle group is equated, the best benefits came from training each muscle group twice per week. There was a big difference between training the muscle group once and twice, but no significant benefit to training it for a third time. More research into this is required, but it's looking like the upper/lower split or push/pull may have a slight edge when it comes to hypertrophy, over the traditional bodybuilding split allocating a day to each area of the body.

5. Using iPads or backlight devices before bed disrupts sleep

Sleep is a fundamental biological process, with humans spending around a third of their lives asleep! Statistics from the Great British Sleep Survey found as many as 51 per cent of Brits are struggling to fall asleep and get a good nights sleep. Poor sleep is linked to most of the major causes of death and closely liked to being overweight and developing diabetes. People using iPads before bed suppress their evening levels of melatonin by 20 per cent, meaning they take longer (around 10 minutes) to fall asleep, and find it much harder to feel fully awake in the morning than people who read from books.

We find a lot of clients suffer from 'The iPad Hangover'. If putting the iPad or laptop down an hour before bed isn't an option, then download the free extension F.Lux, which will help to filter the blue light that is suppressing melatonin production - we've had great success with this with our clients!

You can read about what we learned in March here. Don't forget to check back next month for the latest research!